Posted on 09/01/2006 10:29:12 AM PDT by Responsibility2nd
And didja notice the source for this article? I guess even tree huggers like fast cars.
Lots of unsprung weight doesn't help the handling.
Need a drawing of the layout. The motors should be toward the centerline with drive shafts going to each wheel.
British... and engineering... dont really go hand in hand.
The blance of weight = power is overblown.
When they put this system on a Hummer/Excursion/F-250/HD2500 and it works as successfully, then they will have my undivided attention.
I've wondered for years why nobody has tried a diesel/electric combo in a car. Seems like a great way to take advantage of the torque of an electric and the efficiency of a diesel. Use a battery and some sort of capacitor to buffer the electric demand, and let the diesel run at a constant most-efficient rpm in the background.
Motors ~in~ the wheels is how this stuff will end up, IMHO. Computer control of exact torque supplied to each wheel as needed for acceleration or braking... the thing would drive like it was on rails.
Neat stuff, someday...
"It has motors in its wheels"
GM has an experimental fuel cell platform which uses the same idea, motors at each wheel. Incredible tourque. Variable input does away with the need for a traditional transmission, thus hundreds of pounds shed from the chassis.
Motors on individual tires should also simplify a stability control system and make it easier to detect wheel slippage and counter it.
With a well designed control system and good tires, such a car should be able to have amazing acceleration.
However, I suspect the costs are still going to be extremely prohibitive.
Large banks of Li-Ion batteries like what they appear to be using likely cost more that a standard Mini, and they have a limited recharge cycle and will have to be replaced.
I'm also curious how they have addressed the more obvious downsides of putting the motor in the wheels.
The wheels of a car are regularly partially immersed in water, snow, slush, and mud. The are also subject to much harsher shock and vibration than the main part of the car because the suspension system dampens such forces.
Even if these motors are highly efficient as both motors and generators (when braking) they are going to generate a lot of heat, and dissipating that heat adds to the difficulty of sealing the environment out of the motor, while also creating a harsher environment for the sensors and electronics that will be part of the system.
Removing the need for a drive shaft reduces weight and complexity, but it also puts the motor itself in a much harsher environment.
If they aren't addressing those problems, then all the horsepower, fuel mileage, and range statistics don't mean much of anything because it's not designed to work in a real environment.
"I've wondered for years why nobody has tried a diesel/electric combo in a car"
Ha! Diesel is still over 3.00/gal in Tulsa! How about Natural Gas and Electric? There's the ticket!
Sounds like fun.
it's a sad world we live in when they have to put these type of caveats in their press releases.
Hybrid technology like this could be huge. They need to gear it towards SUV/trucks to achieve the most benifits, though.
Doubling the economy of an SUV saves three times more fuel than switching from a non hybrid crapbox to a hybrid crapbox.
Nope, I believe they're in-wheel motors. Think of the wheel hub & disc rotors being replaced with electro rotors.
Well, sure... it doesn't have to be diesel.
The idea is the same as used in many ships and locomotives. Burn fuel to generate power that drives motors. Electric motors inherently have tremendous torque, so they're great for start/stop accell/decel, just where internal combustion engines aren't. Figure the ideal most efficient rpm speed(s) for whatever engine and let it stay there all the time.
The granularity of control that could be had over individual wheels that each contain an electric motor would be really, really cool.
There was a really nifty idea I saw sometime ago for an electric wheel that was really a spherical shape, in a socket that literally let it turn on any axis. Four of those would give you insane control over the vehicle. It could move sideways just as easily as forward or backward.
They named it the "QED"?? That's what happens when you let the Engineering Department name your new models. But it's pretty funny, nonetheless, especially in light of all the comments on this thread about the problems of putting motors on the wheels, battery performance, cost, etc. Perhaps the car is anything BUT QED.
I suppose they could have a lightweight motor design but if rotor and stator are carried in the wheel the weight would impact performance. Locomotives use something like this; there is a big diesel motor and then electric motors to the drive wheels. Works for GE.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.